Depth charge arming device



Nov. 29, 1960 Filed Feb. 11, 1946 W. S. MACDONALD DEPTH CHARGE ARMINGDEVICE 3 Sheets-Sheet 1 1 III" NIH" Nov. 29, 1960 w. s. MACDONALD2,961,955

' DEPTH came: ARMING DEVICE Filed Feb. 11, 1946 a Sheets-Sheet 2 Nov.29, 1960 w. s. MACDONALD DEPTH CHARGE ARMING DEVICE 3 Sheets-Sheet 3Filed Feb. 11, 19-16 Il II llnited rates Patent assisss Patented Nov.29, 1960 DEPTH CHARGE AmG DEVICE Waldron S. Macdonald, West Newton,Mass.

(Belmont, Mass.) 7

- Filed Feb. 11, 1946, Ser. No. 646,943

7 8 Claims. (Cl. 1027) (Granted under Title 35, U.S. Code (1952), see.266) The present invention relates generally to devices adapted to arm amarine mine, depth charge or the like. More particularly, the inventionrelates to an arming device for a depth charge adapted to fireselectively mechanically or electrically in which the detonating meansthereof is rotated into operative relation with respect to the boostercharge thereof after the depth charge reaches a predetermined depth ofsubmergence thereby to arm the firing circuit and in which the depthcharge is caused to be fired mechanically when it reaches a furtherpredetermined depth of submergence.

It is an object of the present invention to provide new and improvedmeans for moving a detonator into operative relation with respect to abooster charge.

Another object is the provision of a new and improved arming device fora depth charge in which the detonating means thereof is caused to rotatefrom an initial locked position into operative relation with respect tothe booster charge at a predetermined depth of submergence.

Another object is the provision of an arming device of theaforedescribed character in which the detonating means is prevented frommoving into the armed position thereof when sudden increases in pressureof the surrounding water are produced, as by countermining shocks.

Another object is to provide a new and improved arming device for adepth charge having an electrical detonator adapted to be connected intoa firing circuit therefor as the detonator moves into the armed positionthereof.

A further object in a depth charge adapted to be fired selectivelymechanically or electrically as it descends through the water is toprovide new and improved means for firing the depth charge mechanicallyat a predetermined depth of submergence.

Another object is to provide a depth charge adapted to be firedmechanically in which the firing pin therefor is caused forcibly to berotated from an initial locked position into engagement with thedetonating means associated therewith.

A still further object is the provision of a new and improved armingdevice for a depth charge of the above character which may be adjustedto control the depth at which the depth charge is fired mechanically.

A still further object is the provision of a new and improved armingdevice for a depth charge which is rugged in construction, reliable inoperation and economical to manufacture.

Additional objects and advantages will become more clearly apparent asthe description proceeds.

For a more complete understanding of the preferred embodiment ofthepresent invention, reference is made to the following description, takenin connection with the accompanying drawings, of which:

Fig. 1 is a vertical sectional view, with certain parts in elevation, ofthe device of the present invention according to the preferredembodiment thereof;

Fig. 2 is a view similar to Fig. 1 and shows the device of the presentinvention in the armed position thereof;

Fig. 3 is a sectional view taken substantially along the line 3-3 ofFig. 1;

Fig. 4 is a view in elevation taken substantially along the line 4-4 ofFig. 3;

Fig. 5 is a detailed sectional view of the detonators included in thearming device of the present invention; and

Fig. 6 is a fragmentary top view of the present device showing theindicia means associated with the adjustable mechanical firing means.

Referring now to the drawings, wherein like characters of referencerefer to like parts throughout the several views, the numeral 10designates a ring member having a flanged periphery 11 provided with aplurality of holes adapted to receive screws 12 whereby the ring memberis secured to the casing 13 of a depth charge, a suitable gasket 20being arranged intermediate the flange 11 and casing 13 in order toprovide a watertight connection therebetween. The inner end of ringmember 10 is provided with a plurality of threaded openings respectivelyadapted to receive a plurality of posts 14 having threaded extremities.A circular plate 15 is affixed to posts 14 by nuts 16, a booster can 17carrying the booster charge 18 also being secured to the posts by acircular member =19 affixed to the booster can in any suitable manner asby nuts 21. A tubular member 22 is disposed between the wall 23 of thedepth charge casing and the ring member 10 for enclosing the operatingelements of the device of the present invention, member 22 being held infixed position at the inner end thereof by plate 15 and circular member19.

Supported on a shoulder 24 of the ring member 10 by a ring nut 27 andwasher 28 are two flexible diaphragms 25 and 26 composed of any suitablematerial such, for example as a natural or synthetic variety of rubber,the outer diaphragm 25 being in communication with the surrounding waterand depressible by the pressure thereof. Diaphragm 25 is connected todiaphargm 26 by means of a plunger 29 which extends through thediaphragms and which is secured to the outer diaphragm 25 by a shoulder31 formed on the plunger and a nut 32 received on the threaded outerextremity of the plunger, a suitable washer 33 being arranged be tweenscrew 32 and diaphragm 25 for convenience in drawing up tightly thescrew 32. The plunger is secured to diaphragm 26 by means of a washer 34arranged on one side thereof and a spring centering device 35 arrangedon the other side thereof, the plunger having a threaded portion 36adapted to receive a nut 37 whereby the centering device 35 is drawn upagainst diaphragm 26.

A partition '38 is disposed intermediate diaphragms 25 and 26, therebyforming chambers 39 and 4-1, a metered opening 42 being cut into thepartition whereby the chambers are in communication with each other. Thechambers are adapted to be filled with any suitable fluid such, forexample, as brake fluid, which fluid is charged into the chambersthrough a suitable channel 43 provided in the plunger. After filling,the channel is sealed oif as by a plug 44.

As the outer diaphragm 25 is depressed by the pressure of thesurrounding water, fluid from chamber 39 is forced into chamber 41through the opening 42, thereby causing the plunger to move inwardlyagainst an opposing force provided by a coil spring 45 sleeved about theplunger whereby the amount of displacement of the plunger in accordancewith the value of water pressure reacting on diaphragm 25 is controlled.The outer end of spring 45 abuts against the spring centering device 35while the inner end thereof abuts against another spring centeringdevice 46 which is held in position by, and secured in any suitablemanner to, a plurality of ribs 47 extending from the ring member 10.

Suitable tripping means 48 is affixed to the inner end of plunger 29 bymeans of a rivet 49 which is adapted normally to engage a slottedopening 51 provided in a substantially triangularly shaped, rotatableelement 52. Element 52 is rotatably secured to a depending portion 53 ofthe centering device 46 by a pin '54 such that the element is adapted tobe rotated in a clockwise direction as the plunger is caused to moveinwardly. Element 52 is provided with an additional slotted opening 55adapted to receive a pin 56 which extends from one end of a lever 57.The other end of lever 57 is provided with two hubs 58 and 59 throughwhich extends a shaft '61 supported at the ends thereof by uprightportions 62 and 63 formed from plate 15. A biasing spring 64 is sleevedabout hub 59, one end of the spring being hooked over lever 57 and theother end of spring 64 abutting against an upright portion 65 of theplate 15. Formed integrally with and depending from lever 57 is ahousing 66 having a cylindrical bore 67 extending therethrough adaptedto receive an electroresponsive detonator 68, the detonator beingmaintained in the housing by a knurled nut 69 arranged on the upperportion thereof.

By reason of the foregoing arrangement, the electroresponsive detonatoris held in a safe position, displaced angularly from the booster charge,until the depth charge has descended a predetermined distance in thewater and the plunger has moved inwardly a sufiicient distance torelease pin 56. When this occurs, lever 57 is moved by spring 64 intothe position shown in Fig. 2, thereby to place the electroresponsivedetonator in a well 71 provided in the booster charge, a suitableopening 72 being cut into plate 15 to allow passage therethrough of thehousing 66.

A terminal block 73 is secured to plate 15 as by screws 74 and compriseselectrical contacts 75 and 76 adapted to be engaged respectively bycontacts 77 and 78 carried by lever 57 when the detonator 68 is movedinto operative position with respect to the booster charge 18, as shownin Fig. 2. The engagement of the aforesaid contacts connects theelectroresponsive detonator into the depth charge firing circuit,electrical connection being maintained between contacts 77 and 78 andthe detonator by conductors 79 and 81. Conductors 82 and 83 extend fromcontacts 75 and 76 on the terminal block to the depth charge firingcircuit, not shown, through suitable conduit means 84 arranged to passthrough the opening in plate 15 provided by the formation of the uprightportion 63. Contacts 77 and 78 carried by lever 57 are afiixed theretoin any suitable manner as by an insulating plate 85 and screws 86.

In the event that the depth charge is not fired electrically during itsdescent through the water, it is desirable that means be provided forfiring the depth charge mechanically at some greater depth, therebypreventing the depth charge from resting on the bed of the water in anarmed condition.

Accordingly, an additional cylindrical bore 87 is provided in thehousing 66 and is charged with a suitable explosive powder 88 adapted tobe discharged by impact of a suitable firing pin therewith. Anadditional lever 89 is also provided and is sleeved about shaft 61, hubs91 and 92 being formed on the lever in order to prevent lateral movementthereof with respect to the shaft. A biasing spring 93 is sleeved abouthub 92, one end of the spring being hooked around the lever 89 and theother end being arranged to abut against the upright portion 65. An ear94 is formed on the upper end of lever 89 and is adapted to carry afiring pin 95 which is adapted forcibly to engage and explode charge 88when lever 89 is released and driven by spring 93 in a counter-clockwisedirection. I

Lever 89 is provided with a bayonet slot 96 adapted to receive a pin 97formed on the lever 98.. The lever 98 is pivotally mounted about a pin99 which is secured to an arm 101 provided with a substantiallycylindrical, internally threaded portion 102 adapted to receive athreaded portion 103 of rod 104. The ring member 10 is provided with abore 105 through which rod 104 extends, the inner end of the bore beingof a slightly larger diameter and threaded whereby suitable packingmeans 106 is disposed about the rod and held in position by nut 107 toprevent rotary movement of the rod in response to shock, vibration andthe like. The inner end of rod 104 passes through an ear-like portion108 of the upright 62 and a cotter pin 109 is passed through the rod atthe inner end thereof thereby to prevent upward motion of the rod whenit is rotated. For convenience in rotating the rod, a knurled nut 111 isprovided at the upper end thereof externally of the ring member 10.

Rotation of rod 104 causes the pivot point of the lever 98 to be movedup or down in accordance with the direction of rotation of the rod,thereby to bring the lever into or out of proximity with the trippingmeans 48. In order to prevent pin 97 from escaping the bayonet slot 96as lever 98 is moved into proximity with the tripping means 48, abiasing spring 112 is sleeved about pin 99, the ends of the spring beinghooked over lever 98 as shown in dashed outline in Figs. 1 and 2.Lateral movement of arm 101 and lever 98 is prevented by reason of anarrangement comprising a screw 113 passed through an elongated slot 114in the arm 101 and through a threaded hole in depending portion 115 ofthe ring member 10, the screw being tightened sufiiciently to preventsuch lateral movement and still permit raising and lowering of lever 98by rod 104.

In the event that the electroresponsive detonator 68 is not explodedduring the descent of the depth charge, plunger 29 continues to moveinwardly until the tripping means 48 engages lever 98. When this occurs,pin 97 formed on lever 98 is caused to escape the bayonet slot 96thereby releasing lever 89 whereupon the firing pin 95 carried by thelever is driven by spring 93 into engagement with the explosives charge88 thereby causing detonation thereof and of the booster charge 18 andmain charge 116 in succession.

It will be understood that the proximity of the lever 98 with respect tothe tripping means 48 is indicated externally of the arming device bythe provision of indicia means 117, Fig. 6, formed on nut 111 andadapted to cooperate with reference mark 118 whereby one of a pluralityof depths at which the depth charge is to be fired mechanically may bepreselected.

It further will be understood that rapid increases in pressure of thesurrounding water which prevail for a short interval such, for example,which may be produced by countermining explosions and shocks receivedduring launching, will not cause the plunger 29 to be driven inwardly asuflicient distance to release the detonator 66 for rotation for thereason that the flow of fluid between chambers 39 and 41 is restricted.

From the foregoing, it should now be apparent that an arming device fora depth charge has been provided which is well adapted to fulfill theaforesaid objects of the invention.

While the invention has been described in particularity with respect toan example thereof which gives satisfactory results, it readily will beapparent to those skilled in the art, after understanding the invention,that further embodiments, modifications and changes may be made thereinwithout departing from the spirit and scope of the invention as definedby the claims appended hereto.

The invention herein described and claimed may be manufactured and usedby or for the Government of the United States of America forgovernmental purposes without payment of any royalties thereon ortherefor.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:

1. An arming device for a depth charge comprising, in

combination, means responsive to changes in water pressure, an elementoperatively connected to and controlled by said pressure responsivemeans and positionable thereby in accordance with changes in waterpressure, an explosive charge, a rotatably mounted lever having aninitial position out of alignment with said charge and a moved position,electroresponsive detonating means carried by said lever, resilientmeans connected to said lever for rotating said lever into said movedposition thereof thereby to place said detonating means into alignedoperative relation with respect to said explosive charge, and meansforming a part of and controlled by said element for preventing rotationof said lever until the element reaches a predetermined position.

2. A firing mechanism of the character disclosed comprising, incombination, an explosive charge, a spring biased lever mounted forrotation from an initial position out of alignment with said charge to amoved position under power of the spring, electroresponsive detonatingmeans carried by said lever for movement therewith into operativerelation with said explosive charge when the lever is rotated into saidmoved position thereof, releasable means for normally maintaining saidlever in said initial position thereof, a movable element in engagementwith said releasing means for releasing the releasing means when theelement has moved a predetermined distance, and means responsive tochanges in water pressure and in engagement with said element for movingthe element variably in accordance therewith.

3. In a depth charge having a firing circuit, an arming device of thecharacter disclosed comprising, in combination, means responsive tochanges in water pressure, an element operatively connected to saidpressure responsive means and positionable thereby in accordance withchanges in water pressure, an explosive charge, a rotatably mountedlever having an initial position out of alignment with said charge and amoved position, electroresponsive detonating means carried by saidlever, resilient means in engagement with said lever for rotating thelever into said moved position thereof thereby to place said detonatingmeans into operative relation with respect to said explosive charge,switch means including at least one contact element carried by the leverand effective as said lever is rotated into said moved position toconnect said electroresponsive detonating means in said firing circuit,and means including a latch member operatively connected to said elementfor preventing rotation of said lever until the element reaches apredetermined position.

4. A firing mechanism of the character disclosed comprising, incombination, means responsive to changes in water pressure, an elementoperatively connected to said pressure responsive means and movablethereby to different positions selectively in accordance with changes inwater pressure, a rotatably mounted lever having an initial position anda moved position, a percussion cap carried by said lever, an explosivecharge disposed within the firing mechanism out of alignment with saidpercussion cap when the lever is in said initial position, resilientmeans connected to said lever for rotating the lever into said movedposition thereof thereby to place said percussion cap into operativerelation with respect to said explosive charge, means operativelyconnected to said element for preventing rotation of said lever untilthe element reaches a predetermined position, a spring biased leverhaving a firing pin formed thereon and rotatable from an initialposition to a moved position to cause the firing pin forcibly to engageand fire said percussion cap, and releasable means in engagement withsaid element for maintaining said spring biased lever in said initialposition thereof and releasable by said element when a differentpredetermined position has been reached thereby.

5. A firing mechanism of the character disclosed comprising, incombination, hydrostatically controlled means including a movableelement, a rotatably mounted lever operatively connected to saidhydrostatically controlled means and having an initial position and amoved position, a percussion cap carried by said lever, an explosivecharge disposed within the firing'mechanism out of alignment with saidpercussion cap when the lever is in said initial position, resilientmeans engaging said lever for rotating said lever into said movedposition thereof thereby to place said percussion cap into operativealigned relation with respect to said explosive charge, meansoperatively connected to said element for preventing rotation of saidlever until the element has moved a predetermined distance, a springbiased lever having a firing pin formed thereon and rota-table from aninitial position to a moved position to cause the firing pin forcibly toengage said percussion cap, releasable means engaged by said movableelement for maintaining said spring biased lever in said initialposition thereof and releasable by said element upon a difierentpredetermined movement thereof, and means settable at will for varyingthe initial position of said maintaining means with respect to saidelement thereby to vary the depth at which the maintaining means isreleased.

6. In a depth charge adapted to be launched into a body of water havinga firing circuit, a device of the character disclosed and comprising, incombination, an explosive charge, a pivotally mounted lever,electroresponsive detonating means carried by said lever inpredetermined spaced relation out of alignment with said explosivecharge and adapted to be rotated thereby into aligned proximitytherewith, means for releasably locking the lever with said detonatingmeans in said spaced relation, hydrostatically controlled means normallyengaging said locking means for releasing the locking means when agradual increase in the pressure of the surrounding water occurs and forpreventing the release thereof when a rapid increase in the pressure ofthe surrounding water occurs, means operatively connected to said leverand effective as the locking means is released for rotating saiddetonating means into proximity with said explosive charge, and switchmeans including a switching element on said lever and elfective whensaid detonator means is in proximity with said explosive charge toconnect the detonating means in said firing circuit.

7. An arming device for a depth charge comprising, in combination, apressure responsive device, a device connected to said pressureresponsive device and movable thereby in accordance with variations inthe pressure applied thereto, explosive means, a rotatably mounted leverhaving an initial position out of alignment with said explosive meansand a moved position, detonating means on said lever, means connected tosaid lever for rotating the lever into said moved position and aligningthe detonating means with said explosive means, and latching meansconnected to said movable device for preventing rotation of said leveruntil the device reaches a predetermined position.

8. A depth charge arming device comprising, in combination, a firingcircuit, pressure responsive means, an element connected to saidpressure responsive means and movable thereby in accordance with thevariations in the pressure applied thereto, an explosive charge,rotatably mounted lever means having an initial position and a movedposition, resilient means for rotating said lever means,electroresponsive detonating means carried by said lever means, meansfor positioning the detonating means into operative relation with saidcharge as the lever means is rotated, switch means carried by said levermeans for connecting said detonating means in said firing circuit as thelever means is rotated, and means including a latch connected to saidmovable element for preventing rotation of said lever means until theelement reaches a predetermined position.

(References on following page) References Cited in-The file of thispatent UNITED STATES PATENTS Minkler Feb. 15, 1921 Pratt May 15, 1928 5lbhansson Nov. 4, 1930 8 FOREIGN PATENTS France June 28, 1912 GermanyMar.'24, 1921 Great Britain Aug. 2 7, 1926 Italy Apr. 10, 1929 GreatBritain .1. "Oct. 9, 1930

